Conventionally, a drive guide apparatus having a movement unit which moves relative to a base provided with a guide is known. An apparatus using a linear motor as a drive source of a movement unit is also known. Patent document 1 discloses the configuration of a drive guide apparatus using a linear motor as a drive source.
The drive guide apparatus using a linear motor as a drive source has, in the movement unit, a mover which generates a magnetic field when energized. The apparatus also has a stator having a magnet in a portion facing the mover in the base.
By the configuration, the mover is energized and magnetic interaction occurs between the mover and the stator, so that the movement unit can move relative to the base.
With the configuration, the movement unit moves in a state where the mover and the stator are not in contact, so that noise, vibration, and the like can be reduced. Further, since no friction occurs between the mover and the stator, the accelerating performance of the movement unit can be improved.
FIG. 10 illustrates a schematic configuration of a conventional drive guide apparatus. As shown in FIG. 10, the drive guide apparatus has a movement unit 100 constructed by a table 110, movement blocks 120, and a mover 140. A base 210 is provided with a stator 220.
In the base 210, rails 230 (guides) for guiding movement of the movement unit 100 are fixed, and the movement blocks 120 provided for the movement unit 100 is attached to the rails 230.
The movement block 120 is attached to the rail 230 in a state where a certain degree of a preload is applied generally via a rolling member such as a ball or a roller.
The action of applying a preload to the movement block 120 via the rolling member is taken in order to prevent occurrence of backlash between the movement block 120 and the rail 230.
The movement unit 100 further has a heat sink 130 between the mover 140 and the table 110 as shown in FIG. 10. A plurality of heat radiation fins 150 is formed on the heat sink 130.
The heat radiation fins 150 are provided to prevent transmission of heat generated from the mover 140 to the table 110 at the time of making the movement unit 100 move by passing current to the mover 140.
Specifically, if the heat generated by the mover 140 at the time of passing current to the mover 140 is transmitted to the table 110, thermal expansion occurs and the table 110 is deformed. When the table 110 is deformed, the table 110 is curved and the attachment state between the movement blocks 120 and the rails 230 becomes unstable.
As a result, a backlash occurs between the movement blocks 120 and the rails 230, vibration and noise occur, and the life of the drive guide apparatus is shortened.
According to the conventional technique, to prevent heat generated by the mover 140 from being transmitted to the table 110, a heat insulating material 400 is provided between the table 110 and the mover 140.
Further, the heat radiation fins 150 are provided between the mover 140 and the table 110, and heat generated by the mover 140 is radiated by the heat radiation fins 150.
Patent document 1: Japanese Patent Application Laid-Open No. 2004-88981